FileUpload.FileContent Proprietà

Riferimento

Definizione

Spazio dei nomi:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Ottiene un oggetto Stream che punta a un file da caricare usando il controllo FileUpload.

public:
 property System::IO::Stream ^ FileContent { System::IO::Stream ^ get(); };

[System.ComponentModel.Browsable(false)]
public System.IO.Stream FileContent { get; }

[<System.ComponentModel.Browsable(false)>]
member this.FileContent : System.IO.Stream

Public ReadOnly Property FileContent As Stream

Valore della proprietà

Stream

Oggetto Stream che punta a un file da caricare usando la classe FileUpload.

Attributi: BrowsableAttribute

Esempio

Nell'esempio seguente viene illustrato come creare un FileUpload controllo. La FileContent proprietà viene usata per leggere il contenuto del file in una matrice di byte. Quando l'utente fa clic sul pulsante Upload file, il contenuto del file viene visualizzato come byte in una casella di testo nella pagina.

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    protected void UploadButton_Click(object sender, EventArgs e)
    {
        // Specify the path on the server to
        // save the uploaded file to.
        String savePath = @"c:\temp\uploads\";

        // Before attempting to perform operations
        // on the file, verify that the FileUpload 
        // control contains a file.
        if (FileUpload1.HasFile)
        {
            // Append the name of the file to upload to the path.
            savePath += FileUpload1.FileName;
            
            // Call the SaveAs method to save the 
            // uploaded file to the specified path.
            // This example does not perform all
            // the necessary error checking.               
            // If a file with the same name
            // already exists in the specified path,  
            // the uploaded file overwrites it.
            FileUpload1.SaveAs(savePath);
                
            // Notify the user that the file was uploaded successfully.
            UploadStatusLabel.Text = "Your file was uploaded successfully.";
                
            // Call a helper routine to display the contents
            // of the file to upload.
            DisplayFileContents(FileUpload1.PostedFile);
        }
        else
        {
            // Notify the user that a file was not uploaded.
            UploadStatusLabel.Text = "You did not specify a file to upload.";
        }
    }
    void DisplayFileContents(HttpPostedFile file)
    {
        System.IO.Stream myStream;
        Int32 fileLen;
        StringBuilder displayString = new StringBuilder();
     
        // Get the length of the file.
        fileLen = FileUpload1.PostedFile.ContentLength;
            
        // Display the length of the file in a label.
        LengthLabel.Text = "The length of the file is " + 
                           fileLen.ToString() + " bytes.";
   
        // Create a byte array to hold the contents of the file.
        Byte[] Input = new Byte[fileLen];
            
        // Initialize the stream to read the uploaded file.
        myStream = FileUpload1.FileContent;
            
        // Read the file into the byte array.
        myStream.Read(Input, 0, fileLen);
        
        // Copy the byte array to a string.
        for (int loop1 = 0; loop1 < fileLen; loop1++)
        {
            displayString.Append(Input[loop1].ToString());
        }

        // Display the contents of the file in a 
        // textbox on the page.
        ContentsLabel.Text = "The contents of the file as bytes:";

        TextBox ContentsTextBox = new TextBox();
        ContentsTextBox.TextMode = TextBoxMode.MultiLine;
        ContentsTextBox.Height = Unit.Pixel(300);
        ContentsTextBox.Width = Unit.Pixel(400);
        ContentsTextBox.Text = displayString.ToString();

        // Add the textbox to the Controls collection
        // of the Placeholder control.
        PlaceHolder1.Controls.Add(ContentsTextBox);

    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>FileUpload.FileContent Property Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h4>Select a file to upload:</h4>
       
        <asp:FileUpload id="FileUpload1"
           runat="server">
        </asp:FileUpload>
       
        <br /><br />
       
        <asp:Button id="UploadButton" 
            Text="Upload file"
            OnClick="UploadButton_Click"
            runat="server">
        </asp:Button>
        
        <br /><br />
        
        <asp:Label id="UploadStatusLabel"
           runat="server">
        </asp:Label>  
            
        <hr />
        
        <asp:Label id="LengthLabel"
           runat="server">
        </asp:Label>  
        
        <br /><br />
       
        <asp:Label id="ContentsLabel"
           runat="server">
        </asp:Label>  
        
        <br /><br />
       
        <asp:PlaceHolder id="PlaceHolder1"
            runat="server">
        </asp:PlaceHolder>        
    </div>
    </form>
</body>
</html>

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    Sub UploadButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        ' Specify the path on the server to
        ' save the uploaded file to.
        Dim savePath As String = "c:\temp\uploads\"
            
        ' Before attempting to perform operations
        ' on the file, verify that the FileUpload 
        ' control contains a file.
        If (FileUpload1.HasFile) Then
            
            ' Append the name of the file to upload to the path.
            savePath += FileUpload1.FileName
            
            ' Call the SaveAs method to save the 
            ' uploaded file to the specified path.
            ' This example does not perform all
            ' the necessary error checking.               
            ' If a file with the same name
            ' already exists in the specified path,  
            ' the uploaded file overwrites it.
            FileUpload1.SaveAs(savePath)
                
            ' Notify the user that the file was uploaded successfully.
            UploadStatusLabel.Text = "Your file was uploaded successfully."
                
            ' Call a helper routine to display the contents
            ' of the file to upload.
            DisplayFileContents(FileUpload1.PostedFile)
        Else
            ' Notify the user that a file was not uploaded.
            UploadStatusLabel.Text = "You did not specify a file to upload."
        End If

    End Sub

    Sub DisplayFileContents(ByVal file As HttpPostedFile)
            
        Dim myStream As System.IO.Stream
        Dim fileLen As Integer
        Dim displayString As New StringBuilder()
        Dim loop1 As Integer
            
        ' Get the length of the file.
        fileLen = FileUpload1.PostedFile.ContentLength
            
        ' Display the length of the file in a label.
        LengthLabel.Text = "The length of the file is " _
                           + fileLen.ToString + " bytes."
            
        ' Create a byte array to hold the contents of the file.
        Dim Input(fileLen) As Byte
            
        ' Initialize the stream to read the uploaded file.
        myStream = FileUpload1.FileContent
            
        ' Read the file into the byte array.
        myStream.Read(Input, 0, fileLen)
            
        ' Copy the byte array to a string.
        For loop1 = 0 To fileLen - 1
            displayString.Append(Input(loop1).ToString())
        Next loop1
            
        ' Display the contents of the file in a 
        ' textbox on the page.
        ContentsLabel.Text = "The contents of the file as bytes:"
            
        Dim ContentsTextBox As New TextBox
        ContentsTextBox.TextMode = TextBoxMode.MultiLine
        ContentsTextBox.Height = Unit.Pixel(300)
        ContentsTextBox.Width = Unit.Pixel(400)
        ContentsTextBox.Text = displayString.ToString()
            
        ' Add the textbox to the Controls collection
        ' of the Placeholder control.
        PlaceHolder1.Controls.Add(ContentsTextBox)

    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>FileUpload.FileContent Property Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h4>Select a file to upload:</h4>
       
        <asp:FileUpload id="FileUpload1"
           runat="server">
        </asp:FileUpload>
       
        <br /><br />
       
        <asp:Button id="UploadButton" 
            Text="Upload file"
            OnClick="UploadButton_Click"
            runat="server">
        </asp:Button>
        
        <br /><br />
        
        <asp:Label id="UploadStatusLabel"
           runat="server">
        </asp:Label>  
            
        <hr />
        
        <asp:Label id="LengthLabel"
           runat="server">
        </asp:Label>  
        
        <br /><br />
       
        <asp:Label id="ContentsLabel"
           runat="server">
        </asp:Label>  
        
        <br /><br />
       
        <asp:PlaceHolder id="PlaceHolder1"
            runat="server">
        </asp:PlaceHolder>        
    </div>
    </form>
</body>
</html>

Commenti

La FileContent proprietà ottiene un Stream oggetto che punta a un file da caricare usando il FileUpload controllo . Utilizzare la FileContent proprietà per accedere al contenuto del file. Ad esempio, è possibile usare l'oggetto Stream restituito da questa proprietà per leggere il contenuto del file come byte e archiviarli in una matrice di byte.

Si applica a